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Diffstat (limited to '')
-rw-r--r-- | dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/shootout/pidigits.c | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/shootout/pidigits.c b/dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/shootout/pidigits.c new file mode 100644 index 0000000..9cbcae4 --- /dev/null +++ b/dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/shootout/pidigits.c @@ -0,0 +1,125 @@ +// +build ignore + +/* +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are met: + + * Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + + * Redistributions in binary form must reproduce the above copyright + notice, this list of conditions and the following disclaimer in the + documentation and/or other materials provided with the distribution. + + * Neither the name of "The Computer Language Benchmarks Game" nor the + name of "The Computer Language Shootout Benchmarks" nor the names of + its contributors may be used to endorse or promote products derived + from this software without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" +AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE +LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR +CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF +SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS +INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN +CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) +ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +POSSIBILITY OF SUCH DAMAGE. +*/ + +/* The Computer Language Benchmarks Game + http://shootout.alioth.debian.org/ + + contributed by Paolo Bonzini & Sean Bartlett + modified by Michael Mellor +*/ + +#include <stdio.h> +#include <stdlib.h> +#include <gmp.h> + +static mpz_t numer, accum, denom, tmp1, tmp2; + +static int extract_digit() +{ + if (mpz_cmp(numer, accum) > 0) + return -1; + + /* Compute (numer * 3 + accum) / denom */ + mpz_mul_2exp(tmp1, numer, 1); + mpz_add(tmp1, tmp1, numer); + mpz_add(tmp1, tmp1, accum); + mpz_fdiv_qr(tmp1, tmp2, tmp1, denom); + + /* Now, if (numer * 4 + accum) % denom... */ + mpz_add(tmp2, tmp2, numer); + + /* ... is normalized, then the two divisions have the same result. */ + if (mpz_cmp(tmp2, denom) >= 0) + return -1; + + return mpz_get_ui(tmp1); +} + +static void next_term(unsigned int k) +{ + unsigned int y2 = k*2 + 1; + + mpz_mul_2exp(tmp1, numer, 1); + mpz_add(accum, accum, tmp1); + mpz_mul_ui(accum, accum, y2); + mpz_mul_ui(numer, numer, k); + mpz_mul_ui(denom, denom, y2); +} + +static void eliminate_digit(unsigned int d) +{ + mpz_submul_ui(accum, denom, d); + mpz_mul_ui(accum, accum, 10); + mpz_mul_ui(numer, numer, 10); +} + +static void pidigits(unsigned int n) +{ + int d; + unsigned int i = 0, k = 0, m; + mpz_init(tmp1); + mpz_init(tmp2); + mpz_init_set_ui(numer, 1); + mpz_init_set_ui(accum, 0); + mpz_init_set_ui(denom, 1); + + for(;;) + { + do { + k++; + next_term(k); + d = extract_digit(); + } while(d == -1); + + putchar(d + '0'); + + i++; + m = i%10; + if(m == 0) + printf("\t:%d\n", i); + if(i >= n) + break; + eliminate_digit(d); + } + + if(m) { + m = 10 - m; + while(m--) + putchar(' '); + printf("\t:%d\n", n); + } +} + +int main(int argc, char **argv) +{ + pidigits(argc > 1 ? atoi(argv[1]) : 27); + return 0; +} |